1. Field of Invention
This invention relates to protein containing single cell microorganisms. More particularly, this invention relates to food ingredients made by codrying yeast with whey. Also this invention relates to foods prepared using the codried yeast-whey product. More particularly this invention also relates to a process used to prepare the codried yeast-whey product.
2. Description of the Prior Art
A number of bio-synthetic processes have been created to produce protein containing foods from microorganisms. Yeast is a microorganism which may be grown in quantity to produce a multifunctional food product. In some applications yeast suffers from the disadvantage that it retains an undesirable yeast flavor and character.
Whey is a waste product of the dairy industry. Whey is a liquid with suspended solids which remain after the solid cheese is recovered. In general whey is not usable as human food. most of the world's whey is wasted.
Raw whey contains about 5% by weight dairy solids. Condensed whey can contain solids ranging from about 30% to about 70% by weight. Whey can be a nutritious food for humans if processed into an edible food.
However whey, like yeast, when individually dried retains an unpleasant flavor and character. Also whey cannot be dried in a single step to a suitable non-hygroscopic powder. In some food applications the whey retains poor functionality and flavor.
Thus a need existed for a treatment of yeast and whey which would improve the properties of the yeast and the whey. Accordingly it is an object of the invention to utilize whey which is generally wasted. It is also an object of the invention to provide a process which dries whey in conventional single step drying methods. Another object of the invention is to produce a product which does not exhibit the unpleasant flavors of yeast and whey. Another object of the invention is to produce a food ingredient which increases cooking yields in some food systems.
Patents to which the invention relates include U.S. Pat. Nos. 2,809,113; 3,720,519; and 3,728,128.
U.S. Pat. No. 2,809,113 relates to fermenting whey with microorganisms to produce high-protein animal feeds. The yeast is grown on numerous substrates including whey. Once the optimum amount of yeast is grown, the cells are harvested and the cell walls are broken. The protein rich material can be recovered in a liquid state to be added to animal feeds, or the liquid can be spray dried to produce a powder food.
U.S. Pat. No. 3,720,519 relates to production of a flavor potentiator comprising dried yeast fermented whey. A flavor potentiator is a substance when added to foods enhances and increases the material food flavor. This specific flavor potentiator is formed by microbiologically altering whey. The whey is fermented with a culture of yeast. The fermented whey when dried to low moisture content functions as a flavor potentiator.
U.S. Pat. No. 3,728,128 describes the production of a bland whey product. Growing yeast on whey substrate produces a product which eliminates the strong flavor and odor present in whey. The cheese whey is placed in an aerobic vessel, warmed and inoculated with yeast cells. Oxygen is supplied to permit assimilation of the whey. The yeast is allowed to grow to the optimum amount. The medium containing the yeast whey product is pasteurized and spray dried to a bland flake. The food is suitable for human consumption.